Can the Degree of Crystallinity of Ball Milled Mg2Ni Intermetallic Compound Decide its Electrochemical Characteristics?

Abstract

Nanostructured Mg2Ni intermetallic compounds were synthesised by high energy ball milling. Effect of milling time on structure and surface morphology of milled powders were studied using X-ray diffraction and scanning electron microscopy. Crystallite size and degree of crystallinity were confirmed using transmission electron microscopy and selective area electron diffraction analysis. In order to understand the effect of milling time on reaction rates, Differential Thermal Analysis is performed. Thermal profiles of 30 h milled powders indicate lower activation energy. Cyclic voltammetry, electrochemical impedance spectroscopy and charge-discharge studies were carried out to understand the electrochemical performance of prepared electrode materials. 30 h milled electrode material delivers maximum discharge capacity with superior capacity retention after 20 cycles at 20 mA g-1.